The distinguishing mark of Calvinism as over against all other systems lies in its doctrine of ‘efficacious grace,’ which, it teaches, is the undeserved, and therefore gratuitous, and therefore sovereign mercy of God, by which he efficaciously brings whom he will into salvation. Calvinism is specifically the theology of grace; and all are properly Calvinists who confess the absolute sovereignty of God in the distribution of his saving mercy.
– From A. A. Hodge (1877), revision by B. B. Warfield (1893), “Calvinism,” for Johnson’s Universal Encyclopedia (1893), in Selected Shorter Writings of Benjamin B. Warfield, ed. John E. Meeter.